In the field of embroidery sewing machines, a typical problem encountered in sewing embroidery patterns on a workpiece cloth seized by an embroidery frame is gathering of workpiece cloth. Gathering occurs depending on the type of workpiece cloth used and the type of embroidery pattern sewn, and undesirably results in poor quality embroidery patterns. This is particularly noticeable in cases where a pattern is initially sewn with fill stitches, also known as tatami stitches, and thereafter outlined with run stitches, in which case the workpiece cloth tends to gather toward the direction in which the fill stitches are formed. This causes unwanted space to be created between the fill stitches and the outline, resulting in poor look and feel of the embroidery. One conventional solution to such problem is to thermally adhere an interlining coated with thermal adhesives like hot melt on the underside of the workpiece cloth to prevent gathering and puckering of the workpiece cloth.
For example, JP H06-101159 A (hereinafter referred to as patent document 1) discloses, as can be seen typically in pages 2 to 3 and FIG. 1, a method of embroidery processing in which a support is provided for reinforcement of stretch fabric and thin, pucker-prone fabric. The reference exemplifies such support with a film having an adhesive coating on one side which is superimposed on the underside of a fabric. The fabric and the film are thereafter adhered together with an electric iron or electric solder to form an integrated workpiece. Then, the workpiece is secured on the embroidery frame to execute embroidery sewing. The fabric being integral with the film is given reinforced rigidity, and thus, local fabric puckering originating from tensioning of embroidery seams can be prevented.
The embroidery processing method described in patent document 1 requires a preparatory step prior to embroidery sewing in which the fabric and the film are superimposed and integrated by way of thermal adhesion effected by the heat applied by electric iron or electric solder. Thus, time expended on adhesion will increase proportionate to the size of the embroidery pattern and pose increased complexity in the preparatory step, which in turn leads to problems such as poor overall work efficiency.